symbolism of the light in gothic cathedrals
During the Romanesque period of architecture (just before the Gothic), cathedrals were often very dark because they could only put in small windows due to the weight of the stone and height of the cathedral. At the beginning of the Gothic period, the abbot of St. Denis, Suger (1081-1151), had an idea that the space of worship would have a shape that says something about the nature of God. This led to the darkness inside churches begin a big problem. Light has always been a principle of the divine image and it illuminates our way in the world. In the Gospel of John, Jesus calls himself "The Light of the World" (John 8:12). So, if the space for worship must reflect the nature of the God that is to be worshiped, then light is a very important aspect. In fact, it is the very nature of God himself. As far as the problem of the weight of the walls, the architects of the Gothic world found that a pointed arch was more stable, which allowed for bigger windows and higher ceilings. A couple good examples that epitomize the new focus on light are Amiens Cathedral, c. 1218-47, and La Sainte Chapelle, c. 1243-48.